Fuel rail assembly

ABSTRACT

A fuel rail assembly has a pair of fuel rail bodies each of which has a bore extending parallel to the fuel supply passage. Each bore has a plug dividing the bore into inlet and discharge regions. The inlet regions are interconnected by an inlet crossover tube, and each inlet region opens to its associated supply passage through a window and a restriction at one end of the associated fuel rail body to balance fuel flow to the supply passages. At the other end of each fuel rail body, a cross bore extends through the discharge region to the supply passage, and discharge tubes received in the cross bores discharge fuel from the supply passages to a pressure regulator.

TECHNICAL FIELD

This invention relates to an improved fuel rail assembly for supplyingfuel to a V-engine.

BACKGROUND

In a fuel rail assembly for a V-engine, a pair of fuel rail bodies areoften employed to support and supply fuel to a plurality of fuelinjectors, each of which delivers fuel to the inlet port of anassociated engine combustion chamber. Each fuel rail body has socketsfor the injectors which are intersected by a supply passage extendingfrom an inlet region to a discharge region. The inlet regions of thefuel rail bodies are interconnected by a crossover tube to receive fuelfrom a common source, and the discharge regions of the fuel rail bodiesare connected by crossover and/or adapter tubes to a common pressureregulator.

SUMMARY OF THE INVENTION

This invention provides an improved fuel rail assembly suitable forsupplying fuel to an automotive V-engine.

In a preferred embodiment of a fuel rail assembly provided by thisinvention, each of the fuel rail bodies has a bore which parallels andis connected at each end to the supply passage and is divided by a plugto form the inlet and discharge regions. By employing a separate borefor the inlet and discharge regions, the tube connections may be placedclose together to efficiently employ the space available for the fuelrail assembly.

The details as well as other features and advantages of a preferredembodiment of this invention are set forth in the remainder of thespecification and are shown in the accompanying drawings.

SUMMARY OF THE DRAWINGS

FIG. 1 is a plan view of a preferred embodiment of a fuel rail assemblyemploying this invention, with parts broken away to illustrate theconnections between the supply passage and the inlet and dischargeregions.

FIG. 2 is a rear view of the FIG. 1 assembly, illustrating itsconnection to the engine manifold.

FIG. 3 is a left side view of the FIG. 1 assembly, with parts brokenaway to illustrate the intersection of the supply passage and theinjector sockets.

FIG. 4 is an enlarged sectional view taken along line 4--4 of FIG. 1,showing a fitting for supplying fuel to the inlet region of therighthand fuel rail body.

FIG. 5 is an enlarged sectional view taken along line 5--5 of FIG. 3,showing the crossover tube interconnecting the inlet regions of the fuelrail bodies.

FIG. 6 is an enlarged sectional view taken along line 6--6 of FIG. 3,showing the crossover tube connecting the discharge region of thelefthand fuel rail body to the pressure regulator.

FIG. 7 is an enlarged sectional view taken along line 7--7 of FIG. 1,showing the construction of the pressure regulator.

FIG. 8 is an enlarged fragmentary view of a portion of FIG. 1, showingthe adapter tube connecting the discharge region of the righthand fuelrail body to the pressure regulator.

THE PREFERRED EMBODIMENT

Referring to the drawings, a fuel rail assembly 10 includes righthandand lefthand fuel rail bodies 12 and 14 interconnected by an inletcrossover tube 16 and also includes a pressure regulator 18 having abase 20 connected to the lefthand fuel rail body 14 by a dischargecrossover tube 22.

Each fuel rail body 12 and 14 has a supply passage 24 intersecting fourinjector sockets 26. Each injector socket 26 receives an injector 28which is retained by a clip 30.

Each fuel rail body also has a bore 32 parallel to supply passage 24.Each bore 32 is divided by a cup plug 34 to form an inlet region 36forward of plug 34 and a discharge region 38 rearward of plug 34. A fuelinlet fitting 40 provides fuel to the inlet region 36 of righthand fuelrail body 12, and inlet crossover tube 16 interconnects the inletregions 36 to provide fuel to the inlet region 36 of lefthand fuel railbody 14.

At the forward end of each fuel rail body 12 and 14, the inlet region 36formed by each bore 32 is connected to supply passage 24 through amachined window 42, and a cup restrictor 44 limits fuel flow from eachinlet region 36 to its associated supply passage 24 to thereby balancefuel flow through the lefthand and righthand fuel rail bodies 12 and 14.

At the rearward end of each fuel rail body 12 and 14, a cross bore 46extends through bore 32 to connect supply passage 24 with dischargeregion 38. Discharge crossover tube 22 is received in the cross bore 46of lefthand fuel rail body 14 to connect the associated discharge region38 to a bore 47 formed in pressure regulator base 20. Bore 47 isconnected to a pressure regulator chamber 48. A discharge adapter tube50 is received in the cross bore 46 of the righthand fuel rail body 12to connect the associated discharge region 38 to a bore 51 formed inpressure regulator base 20 which also leads to chamber 48.

It will be appreciated, therefore, that fuel flows from inlet fitting 40to the inlet region of righthand fuel rail body 12, and from therethrough inlet crossover tube 16 to the inlet region 36 of lefthand fuelrail body 14. From inlet regions 36, fuel flows through restrictors 44and windows 42 to supply passages 24. Injectors 28 deliver fuel fromsupply passages 24, and the excess fuel flows through cross bores 46 todischarge regions 38 and then through discharge tubes 22 and 50 andbores 47 and 51 to pressure regulator chamber 48.

Pressure regulator 18 includes a valve 52 positioned by a diaphragm 54to control fuel flow from chamber 48 past a valve seat 56 to a dischargefuel fitting 58. Valve 52 is positioned to maintain a desired pressurein chamber 48 and thus in discharge regions 38 and supply passages 24.

Pressure regulator 18 is mounted to righthand fuel rail body 12 by abracket 60. Bracket 60 wraps over both the top and the bottom ofpressure regulator base 20 and is staked into openings 62 in base 20 asshown at 64 for permanent retention by base 20. Screws 66 secure bracket60 to fuel rail body 12 and further secure bracket 60 to pressureregulator base 20.

Crossover pipes 16 and 22 are secured to lefthand fuel rail body 14 by aretainer 68 and a screw 70, and discharge crossover pipe 22 is securedto pressure regulator base 20 by a retainer 72 and a screw 74. Inletcrossover pipe 16 is shown here as secured to righthand fuel rail body12 by bracket 60, but it will be appreciated that inlet crossover pipe16 could be secured to righthand fuel rail body 12 by a separateretainer and screw.

Brackets 76 secure fuel rail assembly 10 to the engine manifold 78. Thetips of injectors 28 are received in openings 80 in manifold 78 to allowinjectors 28 to deliver fuel for mixture with the air flowing to theengine combustion chambers.

A groove 82 formed along the inside of each fuel rail body 12 and 14allows the wiring for injectors 28 to be nestled into and retained byfuel rail bodies 12 and 14.

It should be appreciated that fuel rail assembly 10 includes featuresclaimed in copending applications Ser. No. 410611 filed Aug. 23, 1982 inthe name of L. H. Weinand, Ser. No. 410612 filed Aug. 23, 1982 in thenames of T. J. Atkins, M. J. Field and D. J. Lamirande, Ser. No. 410641filed Aug. 23, 1982 in the names of T. J. Atkins, M. J. Field and D. J.Lamirande, Ser. No. 597080 filed Apr. 5, 1984 in the names of T. G.Elphick, E. S. Eshleman and M. J. Field, Ser. No. 622952 filed June 21,1984 in the names of T. J. Atkins, M. J. Field and A. J. Makusij, andSer. No. 622954 filed June 21, 1984 in the name of M. J. Field.Reference should be made to the disclosures of those applications foradditional details of fuel rail assembly 10.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A fuel rail assemblycomprising a pair of fuel rail bodies each having a fuel supply passageand a bore substantially parallel to said passage, each of said boreshaving a plug dividing the bore into an inlet region and a dischargeregion, one of said fuel rail bodies having an inlet fuel fitting forproviding fuel to the associated inlet region, an inlet crossover tubefor fuel flow from the inlet region of said one fuel rail body to theinlet region of the other fuel rail body, each of said fuel rail bodieshaving a window for fuel flow from the associated inlet region to oneend of the associated supply passage and including a restriction forbalancing the fuel flow through said inlet regions to said supplypassages, each of said fuel rail bodies further having a connection forfuel flow from the other end of the associated supply passage to theassociated discharge region and wherein at least one of said connectionsis formed by a cross bore extending through the associated dischargeregion to the other end of the associated supply passage, and adischarge tube received in said cross bore for discharging fuel fromsaid discharge region, whereby said inlet crossover tube and saiddischarge tube are disposed closely adjacent one another to minimize thespace required for the fuel rail assembly.